I've used this strategy several times with electronic items and got away with 2% to 7% more discount off the tag price or extra freebies like powerbank or memory card. Unlike foods and clothes, electronic gadgets are non-essentials and are usually high ticket items so sales agents are more willing to part with a little commission just to make the sale. Who says it is prohibited? My parents thought so too but times have changed because of the stiff competition. Of course, bargaining at malls is different from bargaining at flea markets. I typically ask if they can give me a dealer's discount or if there's a dealer's promo for an item or brand.